1. Field of the Invention
The invention relates to a method for fitting a resilient hinge of a spectacle frame and to a resilient hinge which is designed for implementation of such a method.
More particularly, the invention relates to a method for fitting a resilient hinge of a spectacle frame, comprising a step for putting a spring thruster into place in a first component and a step for articulating the first component on a second component via a rotational shaft. The fitting is such that an arm of the frame, which is integral with one of the components, is pivoted relative to a surface of the frame which is integral with the other component by displacing the thruster in translation in the first component against the compression of the spring.
2. Description of the Related Art
In this well-known type of fitting, the thruster is thrust against the compression of the spring in order to articulate the two components with the rotational shaft. The removal or loss of the rotational shaft releases the thruster, which escapes from the first component by means of the relaxation of the spring. There is therefore a risk of losing the thruster and the spring, since it is understood that these parts have small dimensions.
In order to eliminate this disadvantage, document FR 2 519 434 published on Jul. 8, 1983 describes a method for fitting a resilient hinge for a spectacle frame wherein, after the step of putting the thruster into place, a the thruster in the first component against the compression of the spring. This pin is withdrawn after the step of articulation of the components by means of the rotational shaft. In other words, this arrangement is designed to retain the thruster temporarily during fitting or removal of the resilient hinge. In the event of loss of the rotational shaft during use of the frame, the thruster escapes from the first component by means of the relaxation of the compression spring.
Document FR 2 334 808 published on Jul. 8, 1977 describes a method for fitting a resilient hinge for an optical frame, wherein the thruster and the spring are introduced into a case and the case is fitted in hot conditions into a first component of the frame before the latter is articulated on a second component via a rotational shaft. The step by means of which the case is rendered integral with the first component is necessary in order to close the case and thus to prevent the thruster permanently from escaping in the event of withdrawal or loss of the rotational shaft. In addition, a separate case of the first component complicates the design of the resilient hinge itself.
Document U.S. Pat. No. 5,515,575 published on May 14, 1996 describes another method for fitting a resilient hinge of a spectacle frame, which makes it possible to retain the thruster permanently in one of the components of the hinge. According to this document, the thruster is put into place by being made to slide into an aperture in the component, against the compression of the spring. During this step, it is necessary to introduce lugs of the thruster in corresponding grooves in the aperture in the component. Then the thruster is subjected to rotation of 90xc2x0 for example, in order to offset the lugs relative to the grooves, such that the thruster is retained permanently in the component. Putting the thruster into place in the thruster. A thruster which is provided with lugs and a component which has an aperture provided with corresponding grooves in this case also complicate the design of the resilient hinge itself.
One of the objects of the invention is to provide simplification in comparison with the known methods for fitting a resilient hinge of a spectacle frame, one of the components of which comprises a spring thruster. More particularly the invention relates to simplification of the step of putting the thruster into place in the component, taking into account the requirement to retain the thruster permanently in the component. The invention also relates to a method which provides simplification during removal of the resilient hinge. The invention further relates to a method for fitting a resilient hinge which provides simplification of the design of the hinge itself, in particular relative to the thruster and the component in which it is put into place.
For this purpose, the invention relates to a method for fitting a resilient hinge of a spectacle frame, comprising a step for putting a spring thruster into place in a first component and a step for articulating the first component on a second component via a rotational shaft, such that an arm of the frame, which is integral with one of the components, pivots relative to a surface of the frame which is integral with the other component by displacing the thruster in the first component against the compression of the spring, characterised in that the first component is opened by resilient deformation, the spring thruster is introduced into the first component, and the latter is closed around the thruster such as to retain the latter by resilient gripping against the compression of the spring.
According to this method the component closes as a resilient gripper around the thruster such as to keep the latter abutted against the compression of the spring. It will be appreciated that the first component can be closed by resilient gripping around the thruster when the latter is introduced sufficiently far into the first component. After the introduction of the thruster into the component it is not necessary to impose additional rotation of the thruster relative to the component in order to prevent the thruster from escaping from the latter. The design of the thruster is therefore simpler, since it is not necessary to provide means for retention on the thruster itself. In addition, the thruster is retained permanently by the component in which it is put into place, without making it necessary to fit the thruster into a case and to close the latter by securing it to the component.
According to an advantageous embodiment of the invention, the first component is forced open by the thruster until this component closes by means of resilient gripping around the thruster. This embodiment simplifies further the fitting of the resilient hinge by making the thruster act as a resilient deformation tool for the first component.
Other advantages of the invention will become apparent from reading the description of two embodiments illustrated by the drawings.